A contact lens should be designed to address two primary factors, comfort to the wearer and visual acuity. A traditional approach to contact lens designs, including soft contact lenses, has focused on designing the posterior surface of the lens to approximate the corneal surface. Accordingly, the central zone of the posterior surface has a radius of curvature that approximates the curvature of the central area of the cornea. Since the cornea typically flattens at its periphery, the peripheral portion of the posterior lens surface is flatter than its central zone. In other words, the central zone has a radius of curvature that is smaller, to a predetermined degree, than the radius of curvature of the peripheral zone. This results in a contact lens where the posterior surface is steeper in the central zone and flatter in the peripheral zone.
For this approach, if the lens design does not closely match the corneal surface of a particular wearer, comfort and/or visual acuity can be compromised. In the soft contact lens industry, customized lenses, manufactured to individual needs, have become impractical, particularly in that regimens employing disposable or frequent replacement lenses have gained popularity. In order to ensure that a large population of wearers can be properly fit, a wide variety of lens designs must be produced and inventoried if the objective is to provide lenses having a posterior surface that closely matches an individual's cornea.